Throttle control valves are used in internal combustion engines to regulate air flow. Accurate air flow control is required for stable combustion in the downstream cylinders. Traditional throttle control in an internal combustion engine uses a gate valve design. This produces non-linear and unstable flow, including high turbulence and a high discharge flow loss across the control throttle plate.
A gate valve design in fluid dynamics is well-known to have rough idling control due to its bluff body shape that regulates the passing flow across the bluff body. This shape tends to induce more instability and increase turbulence to the downstream area. Therefore, additional surface features, such as idling control mechanisms, may be needed to modify the orifice pass area for idling control in a gate valve throttle. Past idling control includes preset idle screws and/or solenoid valves with feedback controls in the bypass loops. These extra modifications make throttle body system more complex and also increase manufacturing costs.